package servlet.ogretim;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import siniflar.Ders;
import siniflar.DersOgrenci;
import siniflar.OgretimUyesi;
import vt.Veritabani;

/**
 *
 * @author Bulent
 */
public class DersAyrinti extends HttpServlet {

    /**
     * Processes requests for both HTTP
     * <code>GET</code> and
     * <code>POST</code> methods.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setCharacterEncoding("UTF-8");
        request.setCharacterEncoding("UTF-8");
        HttpSession oturum = request.getSession();
        
        Boolean ogretimDurum = (Boolean) oturum.getAttribute("ogretimDurum");
        if (ogretimDurum == null) {
            ogretimDurum = false;
        }

        if(ogretimDurum){
            ArrayList<DersOgrenci> ogrenciListesi = null;
            int dersid = 0;
            OgretimUyesi ogretim = (OgretimUyesi)oturum.getAttribute("ogretim");
            
            try{
                dersid = Integer.valueOf(request.getParameter("dersno"));
            } catch(Exception e) {
                response.sendRedirect("Dersler");
                return;
            }

            Veritabani vt = new Veritabani();
            Ders dersBilgileri = vt.dersVer(dersid);
            ogrenciListesi = vt.dersiAlanOgrencileriVer(dersBilgileri);

            // bir sorun yoksa diğer sayfaya bilgileri gönder
            if (ogrenciListesi != null) {
                oturum.setAttribute("dersBilgileri", dersBilgileri);
                oturum.setAttribute("ogrenciListesi", ogrenciListesi);
                oturum.setAttribute("ogretimDurum", true);
                
                yonlendir(request, response, "dersayrinti.jsp");
                return;
            } else {
                //oturum.setAttribute("hata", "Hatalı parametreler"); 
                yonlendir(request, response, "dersler.jsp");
                return;
            }
        }
        else{
            oturum.setAttribute("hata", "Sicil no veya şifre hatası oluştu.");
            oturum.setAttribute("ogretimDurum", false);
            yonlendir(request, response, "giris.jsp");
            return;
        }
    }
    
    public void yonlendir(HttpServletRequest request, HttpServletResponse response, String adres)
            throws ServletException, IOException {
        RequestDispatcher dispatcher = request.getRequestDispatcher(adres);
        dispatcher.forward(request, response);
    }
    
    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /**
     * Handles the HTTP
     * <code>GET</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Handles the HTTP
     * <code>POST</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Returns a short description of the servlet.
     *
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>
}
